I don't have 8 blacks on nutaku, count for yourselves! http://i.imgur.com/FyxL43D.png
As for DMM, i guess the 2 blacks is true. Took me 12 summons total. http://i.imgur.com/XLbzcdx.png
And yes the pictures are level sorted since when i took them i needed advice. Not gotten any new blacks on each account after their screenshots were taken!